This invention relates to an arrangement for the relative angle-of-rotation adjustment of a camshaft of an internal-combustion engine with respect to a driving wheel.
A so-called vane cell camshaft adjuster is known from German Patent Document DE 197 45 908 A1. In this case, recesses are provided on the faces of the rotor vanes in which roll-shaped roll bodies are accommodated. These roll bodies are used for reducing the friction forces between the driving wheel and the rotor. Roller bodies are supported on one side directly in the recess and, on the other side, directly at the interior wall of the driving wheel. Furthermore, it is suggested in a modified embodiment to admit pressure oil to a duct leading to the free face of the rotor vane in order to also reduce the friction forces between the driving wheel and the rotor.
It is an object of the invention to improve an arrangement of the above-mentioned type for the relative angle-of-rotation adjustment of a camshaft with respect to its driving wheel such that the friction power generated between the driving wheel and the rotor is reduced further.
This object is achieved by the claimed invention.
As a result of the pressure chambers provided in the side walls of the rotor vanes, because of the thereby reduced friction surfaces, the friction resistance between the driving wheel and the rotor can be reduced considerably. As a result, a fast, low-wear and reliable adjustment of the desired inlet and outlet times for the valves of the internal-combustion engine can be achieved.
Further advantages and advantageous further developments of the invention are contained in dependent claims and in the description.
Pressure admission to the two pressure chambers provided in a side wall of the rotor vanes advantageously takes place by way of respective openings connected with the pressure spaces adjoining the blades. As a result, the feeding of pressure oil for adjusting the interior part or the rotor can simultaneously be used for the admission of pressure to the pressure chambers provided in the rotor blades. Additional pressure lines for supplying the pressure chambers are therefore not required.